BIOL 121 Lecture : Biol 121- 2010.02.12- Genetics- Inheritance in Humans (Ch. 13, 19, 15).docx
terubarenuka and 39551 others unlocked
44
BIOL 121 Full Course Notes
Verified Note
44 documents
Document Summary
To understand transmission of human traits, must analyze human crosses that already exist b/c making specific crosses will take too long (and ethical issues)! A pedigree (like a family tree) records genetic relationships among the individuals in a family along with each person"s sex and phenotype with respect to the trait in question. Pedigree may reveal whether trait is due to dominant or recessive allele; and whether it is on a sex chromosome or autosome. If a phenotype is due to an autosomal recessive allele, then: individuals with the trait must be homozygous (recessive, if parents of affected individual do not have the trait, they are both heterozygous. Individuals with at least one allele for the trait must have the phenotype. Unless new mutation occurs, any child with the trait must have a parent with the trait. A marker is a trait that appears in people that have a specific disease.